Buckles



F. B. HARLEY BUCKLES Sept. 15, 1959.

2 Sheets-Sheet 1 Filed Aug. 28, 1953 FRANK I3. HARLEY Unite StatesClaims priority, application Great Britain December 24, 1952 11 Claims.(Cl. 24-470) This invention relates to releasable coupling devices forconnecting a strap, tape or the like to another part (for example toanother strap or to the opposite end of the same strap).

One aspect of the invention is concerned with buckles of the typecomprising a body affording a main anchorage for connection to the partto be connected to the strap, a gripping edge extending transversely tothe direction of the applied load and an auxiliary anchorage lyingparallel to the-gripping edge in a regionbetween it and the mainanchorage and movable towards and away from the gripping edge. In such abuckle the strap (assuming the buckle lies horizontally) is passed underthe gripping edge and the auxiliary anchoring edge and back over theauxiliary anchoring edge and under the gripping edge.

An objectof the present invention is to provide an improved form of suchbuckle which is particularly suitable for use Where very high loads areto'be applied, for instance in safety belts, and the lashing ofequipment in aircraft.

In a buckle of this type according to one aspect of the presentinvention the gripping edge affords a concave or hollowed out surface,and means are provided for mounting the auxiliary anchorage in theregion between the main anchorage and the gripping edge parallel to thelatter and opposed to and movable towards and away from the said concavesurface, so that a portion of a strap passed round the auxiliaryanchorage, with its free end portion gripped between its standingportion and the gripping edge, will be pressed into the concave surface,so that the latter partially embraces the said portion of the strapwrapped round a surface of the auxiliary anchorage.

The auxiliary anchorage may be afforded by a bar of oblong sectionhaving a pair of approximately parallel faces and an intervening curved(e.g. semi-cylindrical) face at one end round which the strap iswrapped, and at the opposite end two. rounded corner edges one of whichpresses the strapinto the hollow of the gripping edge.

The auxiliary anchorage may have at its ends projections fitting intoslots in the body of the buckle.

In one form of the invention the auxiliary anchorage is afforded by abar acted on by cams connected to a release member to draw it away fromthe gripping edge. For example the auxiliary anchorage may have at itsends a pair of trunnions extending through slots in the body, andeccentric pins projecting beyond the trunnions and acted on by the camswhich are arranged also to tilt the auxiliary anchorage about the axesof the trunnions. The cams may be carried by the release member which isarranged so as to tend to tilt the whole buckle in such direction 'as tostraighten the strap where it is wrapped round the gripping edge, and atthe same time, through the cams, to rock the auxiliary anchorage in theopposite direction. i

A further aspect of the invention is concerned with an improved form ofquick-release latch of the type comatenr ice prising a body portion forreleasably retaining a subsidiary portion comprising a flat aperturedmember, such as a plate with a hole in it, in which the body portion hasin it a deep flat recess to receive the apertured memher, a bolt toextend through the apertured member in a direction substantially atright angles to it, and manually-operated means arranged to retract thebolt against the action of a spring. Such a release latch isparticularly useful for securing safety belts or the like in aircraft,in which case the latch may be connected to or be integral with a buckleof the type described above.

In such an application it is important that although the latch should bereadily releasable it should engage positively, and there should be nopossibility of the user supposing that it is positively engaged when infact it is only held in place by friction.

In such a construction, as hitherto proposed, the face of the bolt hasbeen inclined to form a ramp enabling it to be thrust back by insertionof the plate, and then to spring forward into the hole in the plate.With such an arrangement there is a possibility that if the plate ispartially inserted so that the hole does not register with the bolt andthe bolt does not spring forward into it, the plate may none the less begripped between the end of the bolt and the opposed part of the body andbe thereby held in position provided no substantial tension is exertedon the latch. If, however, the latch is called upon to withstand anyload it will come apart and hence completely fail to serve its purpose.An object of the invention is to reduce or remove this possibility.

Thus according to one form of the present invention the latch includesalso a catch arranged to hold the bolt in its retracted position but tobe released by insertion 'of the apertured member. The end of the boltwill then be made square, without any inclined surface or ramp.

The invention may be carried into practice in various ways but twospecific embodiments will now be described by way of example withreference to the accompanying drawings in which:

Figure l is a perspective view of one form of buckle embodying thepresent invention,

Figure 2 is a plan view of the buckle of Figure 1,

Figure 3 is a sectional side elevation on the line 3-3 of Figure 2, andshowing a strap passed through the buckle,

Figure 4 is a part sectional side elevation of a buckle with a modifiedform of release latch,

Figure 5 is a side elevation of the buckle of Figure 4 with certainparts removed,

Figure 6 is a side elevation similar to Figure 5 showing the rockinganchorage in two positions, and

Figure 7 is an exploded view of certain parts of the buckle included inboth embodiments. 'In each of the embodiments to be described the bucklecomprises a body formed by two parallel side members 10 interconnectedat each end by two parallel cross members forming a main anchorage 11and a gripping edge 12. The main anchorage 11 is in the form of a blockwhich has in it a deep flat recess 13 to take the part to which thestrap is connected. The quick-release latch by which this part issecured will be described below.

An auxiliary anchorage 14 lies parallel to, and spaced slightly from thegripping edge 12, between it and the mainanchorage 11. As is shownclearly in Figures 4 and 7 the auxiliary anchorage comprises a bar ofsubstantially oblong section comprising a pair of flat parallel sides 15connected by a semi-cylindrical surface 16 at their upper ends, andhaving a pair of rounded corner edges 17 and 18 at the other end. Thisbar has at its ends cylindrical trunnions 19 which are received in openslots 20 in the side members 10.

The cylindrical trunnions 19 merge with the outer, or

upper, semi-cylindrical edge 16 of the auxiliary anchorage so that whenthe buckle is in use, rotation of the auxiliary anchorage about itstrunnions causes the rounded edge 17 to press the strap towards andagainst a surface of the gripping edge. In accordance with the inventionthis surface is hollowed out or formed with a rounded groove 21 toreceive the strap.

The auxiliary anchorage 14 is held into the open ended slots 20, and itsrotation in them is controlled, by a release member 22 in the form of astrip bent to U-shape, The ends 23 of the limbs 24 of the U are pivotedby screws 25 to opposite points 25 on the outside of the side membersbetween the slots and the main anchorage block 11. The limbs 24 extendalong the sides 10 of the body, whilst the base 26 of the U extendsacross the end of the body beyond the gripping edge 12. The base isprovided with an integral tab 27 to facilitate its manual operation.Alternatively the tab may be replaced by a short length of webbing sewnround the base 26 of the U.

The auxiliary anchorage 14 is held in its slots by two pins 28 whichextend from its ends into corresponding holes 29 in the side limbs 24 ofthe U-shaped release member 22. These pins 28 extend from substantiallythe centre point of the auxiliary anchorages oblong sectional ends andare thus situated eccentrically below the trunnions 19, as shown inFigures 5 and 6.

As is shown in Figure 7, the bottoms of the slots 20 in thebody haveinclined surfaces 30 upon which the pins 28 can ride up as the trunnionsrock about their axes. The rotation of the release member 22 about itspivots causes the auxiliary anchorage 14 to rise slightly in its slots20, and, by virtue of the eccentric position of the pins 28 in relationto the trunnions 19, the latter are rotated. In this way a slight upwardrotation of the release member 22 causes the rounded edge 17 of theauxiliary anchorage to be withdrawnfrom the hollow 21 of the grippingedge 12, thus freeing the strap. Two extremepositions of the auxiliaryanchorage are shown in Figure 6.

Thus the operation of the buckle is as follows. As is shown in Figure 3,the free end of a strap 31 is passed under the gripping edge 12 and theauxiliary anchorage 14, passed back over the auxiliary anchorage andunder the gripping edge so that both the free end of the strap 32, and astanding part-33 of it bear against thegripping edge 12, with the freeend between the gripping edge and the standingpart.

The free end of the strap can be pulled through the buckle until therequired-tension is obtained in the stand ing part. The tension inthestanding-part of the strap causes the auxiliary anchorage 14 to turnso that the rounded edge 17 presses the strap into the hollow 21 of thegripping edge 12, thus holding it firmly against slip. Any increase inthe load on the strap Will tend to turn the auixilary anchorage evenfurther so increasing the grip.

The strap can be instantly slackened or released by raising the'U-shaped release member 22, which withdraws the auxiliary anchorage 14from the gripping edge 12,"thus-removing the grip on the strap.

The main anchorage 11, as has already been described has a deep fiatrecess 13 in its end remote from the buckle. This recess receives aflatplate 34 of-generally triangular shape with rounded corners. Theplate and recess 'form the cooperating portions ofa quick release latch.

As is shown in Figures 1 and 2 the plate 34 has in it a slot 35 forreceiving the end of a belt 36 which is securely fastened by beingpassed round and stitched. Where the buckle and latch are employed onasafety belt for aircraftand the like, the end secured to the slot 35may be of the same belt as is secured to the buckle. i

The plate 34 has in it a-hole 37 toreceive a bolt 38 4 which passesthrough a bore 39 in the block. The bolt is surrounded by a spring 40which biasses it downwards to the latched position, as is shown inFigure 3.

An operating member 41 is screwed to the upper end of the bolt 38 so asto turn with it about its axis, and is formed with a helical cam surface42 cooperating with surfaces on the body, so that as it is turned bymeans of its handle 43, it is forced away from the plate 34 and retractsthe bolt 38 with it.

A small bore 44 is formed in the block in a direction parallel to thedirection of insertion of the plate 34 and perpendicular to the axis ofthe bolt 38, to receive a catch in the form of an L shaped pin '45,having a long limb 46, and a short limb 47. The long limb is received inthe bore 44 so that its end projects into a shallow hole (not shown) inthe bolt 38 when the latter is retracted, to keep it retracted.Alternatively it may engage under a shoulder formed on the bolt. Theshort limb '47 projects down into the recess 13 in such a position as tobe engaged by the end 48 of the plate 34 as it is inserted, when itreaches the fully home position in which the bolt 38 can enter the hole37 in it. At this point the plate will retract the L-shaped pin 45, andallow the bolt 38 to be projected by its spring 40 into the engagedposition. 'A small wire spring 49 is arranged behind theL-shaped 'pin45, to urge it toward the bolt 38.

Thus when a tension is applied to the belt instantaneous disconnection'can be effected by retracting the bolt so that the plate member 'isfree to be withdrawn from the block. The catch then snaps home and holdsthe bolt retracted.

The latch can be recngaged by inserting the plate into the body. As theplate is pushed fully home the catch will be retracted and the bolt willsnap forward "to its eng ged position. If however, the user should failto insert the plate fully home'the bolt will be held retractedbythecatch and the plate will not be gripped but will be-complete'lyloose, so that the weight of the belt will cause the latch to fall apartand it will be obvious to the user that it is not engaged and cannot berelied on. In some cases it is just possible that the 'plate may bewithdrawn without retracting the bolt far enough to permit engagement ofthe catch. The only effect of this will be that the'plate cannot then bereinserted without again operating the'operating'member to retract-thebolt.

In an alternative construction shown in Figures 4, 5 and 6 the bolt 38protrudes from the top of'the block and has a pin 50 passing through itdiametrically to afforda fulcrum for a control leverwhich comprises aplate 51 forked at one end to pass under the pin 50 on either side of'the 'bolt 38 and bent to swan-neck form to retain it in place andafford end surfaces about which it'can rock..

*WhatIclaim as my Letters Patent is:

.1. A releasable buckle for connecting a strap to another partcomprisinga body having an axis of symmetry extending in the general direction ofthe applied load on'the strap, said body affording a main anchorage forconnection to the part to be connected to the strap andhaving-anintegral cross member transverse to said axis providing a'gripping-edgewith a concave surface spaced from the main anchorage, a release memberpivotally-mounted'on the body on a transverse axis lying between saidgripping edge and said main anchorage, andan auxiliary anchoragehavingan edge parallel with thegripping edge and pivotally mounted on therelease-member on a transverse axis lying between the pivotal axisthereof and said gripping edge, whereby said edge of theauxiliary-anchorage is capable of movement'in or out of the concavesurface'of the gripping edge and when the strap is passed under thegripping edge around the auxiliary anchorage and back under the grippingedge between the gripping edge and the standing end ofthe strap,tensionapplied-to the standing invention and desire to secure by d andof the strap will tend to move the auxiliary anchorage so that its edgeand hence the strap move further into the concave surface of thegripping edge, while pivoting of the release member with respect to thebody will move the auxiliary anchorage so that its edge moves out of theconcave surface to release the strap.

2. A buckle as claimed in claim 1 in which the release member comprisesa part adapted for manual operation whereby pivoting of the releasemember to free the auxiliary anchorage causes rotation of the auxiliaryanchorage in such a direction as to straighten the strap where it isWrapped around the gripping edge and thereby aid in disengaging thestrap from the buckle.

3. A releasable buckle for comrecting a strap to another part comprisinga body having spaced side portions connected at their ends and endportions afiording both a main anchorage for connection to the part tobe connected to the strap and a gripping edge spaced from the mainanchorage and extending transversely to the direction of the appliedload with a concave surface extending along it, guides formed in thesides of said body at opposite points and a release member pivotallymounted on the body adjacent to but spaced from said guides, and anauxiliary anchorage having an edge parallel with the gripping edge andhaving a pair of trunnions mounted for sliding and rotational movementin said guides, the auxiliary anchorage being pivotally mounted on therelease member eccentrically of the trunnions; whereby when the strap ispassed under the gripping edge around the auxiliary anchorage and backunder the gripping edge between the gripping edge and the standing endof the strap, tension applied to the standing end of the strap will tendto move the auxiliary anchorage so that its edge and hence the strapmove fur ther into the concave surface of the gripping edge, whereuponmanual pivoting of the release member with respect to the body willcause the auxiliary anchorage to rotate about its trunnions to move itsedge away from the gripping edge to release the strap.

4. A buckle as claimed in claim 3 in which the trunnion guides extendoff at an angle to the direction of the applied load and the trunnionsare olfset laterally therein whereby pivoting of the release memberchanges the attitude of the Whole buckle in such a direction as to tendto straighten the strap where it is wrapped around the gripping edge.

5. A buckle as claimed in claim 4 in which the plane of movement of theaxis of the trunnions is at a substantial angle to the perpendicular tothe plane containing the pivotal axes of the release member and of theauxiliary anchorage.

6. A buckle as claimed in claim 3 in which the plane of movement of theaxis of the trunnions is at a substantial angle to the perpendicular tothe plane containing the pivotal axes of the release member and of theauxiliary anchorage.

7. A releasable buckle for connecting a strap to another part comprisinga body affording a main anchorage for connection to the part to beconnected to the strap and having parallel arms supporting a grippingedge spaced from the main anchorage, the gripping edge having a concavesurface facing the main anchorage; and an auxiliary anchorage mounted ontrunnions in grooves formed in the arms extending at a substantial angleto the direction of tension on the strap with an edge parallel with thegripping edge to move as the auxiliary anchorage rotates about itstrunnions in a direction having a substantial component radially of thecurved surface, in which when the strap is passed under the grippingedge around the auxiliary anchorage and back under the gripping edgebetween the gripping edge and the standing end of the strap, tensionapplied to the standing end of the strap will tend to move the auxiliaryanchorage so that its edge and hence the strap move further into theconcave surface of the gripping edge, while rotation of the auxiliaryanchorage about its trunnions will cause the edge of the auxiliaryanchorage to move away from the curved surface of the gripping edge witha substantial radial component and will release the strap, and move mentof the auxiliary anchorage along the grooves accompanying such rotationwill also cause the edge of the auxiliary anchorage to move away fromthe curved surface of the gripping edge with a substantial radialcomponent and will release the strap.

8. A buckle as claimed in claim 7 in which the auxiliary anchorage has across-section which is generally rectangular but is semi-circular at thetop and in which the trunnions project from its ends with half theircylindrical surfaces forming a smooth continuation of the semi-circularpart of the cross-section of the anchorage, the edge which cooperateswith the curved surface of the gripping edge being constituted by one ofthe lower corners of the rectangular section, which is in consequencespaced from the axis of the trunnions.

9. A buckle as claimed in claim 8 in which the curved surface of thegripping edge is substantially symmetrical about a plane parallel withthe plane containing the strap when it is under tension and is flat (thetension plane).

10. A buckle as claimed in claim 9 in which the plane of symmetry of thecurved surface of the gripping edge is spaced from the tension plane andthe trunnion grooves are spaced from the plane of symmetry of the curvedsurface of the gripping edge on the side remote from the tension plane.

11. A releasable buckle for connecting a strap to another partcomprising a body having an axis of symmetry extending lengthwisethereof affording adjacent to an end a main anchorage for connection tothe part to be connected to the strap and having parallel arms rigidlysupporting a transverse strap engaging member provided with a grippingedge spaced from the main anchorage, the gripping edge having a concavesurface facing the main anchorage; a release member pivoted to said armsand an auxiliary anchorage provided with a strap engaging edge parallelwith said gripping edge, auxiliary anchorage having trunnions at itsends mounted in grooves formed in the arms and extending at asubstantial angle to the direction of tension on the strap, saidauxiliary anchorage having pivots eccentric with respect to saidtrunnions engaging holes in said release member, said pivots alsoengaging notches in said grooves, whereby said auxiliary anchorage isconstrained to rotate about its trunnions in a direction having asubstantial component radially of the curved surface until stopped bysaid pivots engaging said notches; whereby when the strap is passedunder the gripping edge around the auxiliary anchorage and back underthe gripping edge between the gripping edge and the standing end of thestrap, tension applied to the standing end of the strap tends to movethe auxiliary anchorage and the portion of the encircling strap adjacentto said strap engaging edge further into engagement with the concavesurface of the gripping edge, and rotation of the auxiliary anchor-ageabout its trunnions until said pivots engage in said notches and stopfurther rotation, whereupon rotation of the auxiliary anchorage in theopposite direction will cause the edge of the auxiliary anchorage tomove away from the curved surface of the gripping edge with asubstantial radial component in the direction to release the strap,while movement of the auxiliary anchorage along the grooves will alsocause the edge of the auxiliary anchorage to move away from the curvedsurface of the gripping edge with a substantial radial component andwill release the strap, in which the auxiliary anchorage has across-section which is generally rectangular but is semi-circular at thetop and in which the trunnions project from its ends with half theircylindrical surfaces forming a smooth continuation of the semi-circularpart of the cross-section of the anchorage,

the edge which cooperates with the curved surface of the gripping edgebeing constituted by one of the lower corners of the rectangularsection, which is in consequence spaced from the axis of the trunnions,the auxiliary anchorage being positioned, when the strap is gripped,with the two sides of its rectangular cross-section which join thesemi-circular top side lying substantially parallel with the axis of thetrunnion grooves.

Ryther Feb. 19, 1918 Clark Apr. 4, 1939 8 Lethern et a1 Sept. 9, 1941Griswold, June 27, 1950 Smith Oct. 24, 1950 Miller Feb. 20, 1951'Elsner, Apr. '1, 1951 Harley Apr. 21, 19531 Davis May 1, 1956 FOREIGNPATENTS Germany Sept. 18, 1924 Austria Apr. 21, 1927 Great Britain Mayl0, 1950 Great Britain Apr. 25, 1951 UL m

